Both of the new mutant strains on SARS CoV2 found in UK and S. Africa have N501Y mutation. The preprint paper quoted below tells this mutation causes stronger interaction between S1 spike protein of the virus and hACE2 while it decreases that with anti spike protein antibody.
It may mean this mutant strains could prevail more efficiently than the original strain and even could be more toxic since it would hinder the antibody interaction to S1 spike protein, that is, neutralizing antibody reaction. As this author mentions, it might be related with the effect of the vaccines.
The other report analyzed the characteristics of antibody produced in infection. There is a kind of IgG antibody which has a negative effect for self defense. The article says it might be the reason why convalescent phase plasma has not given dramatic effect on seriously ill patients.
There are still problems with this pathogen to overcome the outbreak. The N501Y+strain seems to already prevail in various countries. We should be even more cautious not to get infected until the vaccines prove to be effective for the strain.